Report PPAPI plugin load error code to UMA.

base/native_library.h

Index: base/native_library.h
diff --git a/base/native_library.h b/base/native_library.h
index d7513d0b050e181b4df913e276b39051aef5318f..564234ae11dc0d3daa04f918a8a5d700bb4d751d 100644
--- a/base/native_library.h
+++ b/base/native_library.h
@@ -50,11 +50,18 @@ typedef NativeLibraryStruct* NativeLibrary;
 typedef void* NativeLibrary;
 #endif  // OS_*
 
+#if defined(OS_WIN)
+typedef DWORD NativeLibraryLoadError;
+#else
+typedef std::string NativeLibraryLoadError;
+#endif  // OS_WIN

[xhwang, 2014/03/21 19:00:54]

I like this more now because it makes call sites more cleaner.

+
 // Loads a native library from disk.  Release it with UnloadNativeLibrary when
 // you're done.  Returns NULL on failure.
-// If |error| is not NULL, it may be filled in with an error message on error.
+// If |error| is not NULL, it may be filled in on load error if the platform
+// supports it.
 BASE_EXPORT NativeLibrary LoadNativeLibrary(const FilePath& library_path,
-                                            std::string* error);
+                                            NativeLibraryLoadError* error);
 
 #if defined(OS_WIN)
 // Loads a native library from disk.  Release it with UnloadNativeLibrary when